Rear slagging for induction furnace

ABSTRACT

There is disclosed herein a coreless induction furnace disposed on a vertical axis during heating and having a front pouring spout and a rear slagging spout at the upper end thereof. The furnace is mounted in a forwardly pivotable cradle carried by a backwardly tiltable base frame, the base frame being pivoted at the bottom thereof rearwardly of the furnace axis.

I United States Patent 1191 1111 3,790,338 Duca Feb. 5, 1974 [54] REAR SLAGGING FOR INDUCTION 3,311,361 3/1967 Zepernick 266/36, FURNACE 2,783,990 3/1957 Tripmacher et a1.. 263/33 2,587,727 2/1952 "Horswell et a1 13/26 [75] Inventor: William J- Duc a re hi 1,647,787 1/1927 DeZubiria 13/26 2,592,184 4 1952 PI k 263 46 [73] Asslgnee: MagneFherm'c 2,481,699 9/1949 Stifman 263/33 Warren 2,528,571 11 1950 Babcock et a1. 263/33 [22] Filed: Oct. 29, 1971 Primary Examiner--J0hn J. Camby [21] App]. No.. 193,770 Assistant ExaminerHenry C. Yuen [52] US. Cl 432/247, 266/36, 4321/31/5276, '[57] ABSTRACT [51] Int. Cl. F27b 14/02 There is disclosed herein a Coreless induction furnace 58 Field of Search 263/46, 33 A; 266/36, 39; disposed on a vertical axis during heating and having a 13/2 432/247 105 107 108 15 1 7 front pouring spout and a rear slagging spout at the upper end thereof. The furnace is mounted in a for- [56] References Cited wardly pivotable cradle carried by a backwardly tilt- UNITED STATES PATENTS able base frame, the base frame being pivoted at the bottom thereof rearwardly of the fumace axis. 3,458,179 7/1969 ORourke 432/157 3,531,074 9/1970 Zelley et a1 266/36 6 Claims, 3 Drawing Figures 1 REAR SLAGGING FOR INDUCTION FURNACE This invention relates to the induction heating and melting of metal and particularly to means for mounting a coreless induction furnace.

Various means have heretofore been provided for mounting coreless induction furnaces whereby the furnace can be pivoted in a forward direction for pouring the melt and tilted rearwardly for slagging. The upper end of the furnace is generally oriented witn respect to a fixed operationg deck for pouring operations with the remainder of the furnace normally disposed below said operating deck.

Prior mounting means known to the inventor pivot the furnace about a main pivot point whereby, when the furnace is tilted backwardly for slagging, the rear of the furnace drops below the normal operating deck. This means that the slag handling mechanism is below the normal floor-operating level of the deck which makes it difficult to handle. Additionally, some means must be provided to ensure that the furnace remains in its normal operating position'and does not inadvertently fall to its slagging level during normal operation.

The present invention as herein illustrated comprises a base frame having a cradle which carries a coreless induction furnace. The cradle is pivoted to the frame on a horizontal axis disposed adjacent to the pouring spout of the furnace, and means are provided for rotatin g the cradle and furnace forwardly with respect to the frame for pouring. The base frame is pivoted at the bottom thereof rearwardly of the normal vertical axis of the furnace about an axis parallel with the cradle pivot. Means are provided for backdilting the base frame for slagging the furnacethrough a rear slag spout. The base frame pivot is so positioned that the furnace moves both vertically upwardly and horizontally rearwardly whereby the slag spout moves over a slag box on the operating deck and slagging is conveniently done from said operating deck. The center of gravity of the base frame and furnace is such that the frame normally tends to set flat on a horizontal base surface with the furnace disposed on a vertical axis, and there is no possibility of thefurnace inadvertently falling to slagging position.

In view of the foregoing, it is an object of this invention to provide a back-tilting coreless induction furnace assembly whereby rear slagging can be accomplished above the normal operating deck level.

Another object of the invention is to provide an induction furnace assembly of the above type which normally tends to set in an upright position and cannot inadvertently fall to slagging position.

Still another object of the invention is to provide an induction furnace assembly as set forth above wherein thefurnace moves both vertically upwardly and horizontally rearwardly whenback-tilted for slagging.

Yet another object of the invention is to provide an induction furnace assembly having the above features and characteristics wherein the furnace is pivotable forwardly for pouring, with respect to a frame and wherein the frame is tiltable in the opposite direction for back-tilting the furnace.

Other objects of the invention and the invention itself will be understood from the following description of one embodiment thereof as shown in the accompanying drawings in which:

FIG. 1 is a side elevation of the furnace of this invention showing the furnace in back-tilted or slagging position;

FIG. 2 is a front elevation, on a slightly reduced scale, showing the furnace in its normal, level, operating position; and

FIG. 3 is a side elevation similar to FIG. 1 showing the furnace in the pouring position.

Referring now to the drawings in all of which like parts are designated by like reference numerals, an induction furnace assembly generally indicated at 10 comprises a pair of base plates 11, a base frame 12 mounted upon said base plates, a forwardly pivotable cradle 13 mounted at the upper end of said base frame, and a coreless induction furnace unit 14 carried by the cradle 13. The base plates 11 are mounted upon any suitable supporting surface S" disposed substantially below the level of an operating deck D. The operating deck D" has an edgeiportion l spaced from the back of the furnace assembly to which is mounted a rear tilt deck 16 supporting a slag box 17.

The base frame 12 comprises a pair of laterally spaced, vertical columns 20, each said column being connected at the lower end thereof to a pair of spaced, parallel, rearwardly directed horizontal members 21 secured at their forward ends to a common plate 22 which is, in turn, connected to the lower end of a vertical column 20. Upwardly and forwardly angled diagonal braces 23 are respectively connected at their lower ends to the rearwardly directed end portions of the horizontal members 21 and at the upper ends thereof to upper plates 24 mounted adjacent to the upper ends of the vertical columns 20. It will be understood that the columns, members, plates, braces, etc. comprising the base frame are preferably heavy structural steel members such as I-beams or channel-shaped beams which are welded, bolted, riveted or otherwise suitably secured together.

The lower ends of the pair of vertical columns are rigidly secured together by means of a transverse beam 25 (FIG. 2). The upper ends of said vertical columns are provided with bearings 26 for pivotally mounting the forward end .of the cradle 13. The cradle 13 comprises pairs of side frame members 27 and end frame members 28 rigidly secured together and to the induction furnace unit 14 in any suitable manner. Each side of the cradle comprises a pair of parallel side frame members 27 spaced apart and each carrying an upwardly extending bearing plate 29 at its forward end. At each side of the induction furnace assembly 10, the pair of bearing plates 29 overlap the sides of a bearing 26, and a short heavy pivot shaft 30 projects through suitable openings insaid bearing 26 and bearing plates 29 whereby the cradle 13 and induction furnace unit 14 are pivoted at the front of the base frame 12 just above the vertical columns 20.

The induction furnace unit 14 comprises a crucible 33 formed by a suitable refractory lining 34 surrounded by a helical induction heating coil 35 retained by suitable securing means 36 within an outer shell 37. The crucible 33 includes a front pouring spout 38 and a rear slag spout 39. It is covered by a furnace lid 40.

The base frame 12 is pivoted adjacent to the rearmost ends of the base plates 11 rearwardly of the axis of the induction furnace unit 14 by means of bearings 41 disposed between upstanding bearing brackets 42 of said base plates, the bearings and bearing brackets being journalled to each other by means of pivot shafts 43. The bearings 41 are welded or otherwise suitably secured to the rearwardly directed ends of the horizontal members 21 whereby the base frame 12 and the induction furnace unit 14 can be tilted backwardly from the broken line to the full line position shown in FIG. 1.

Power means for back-tilting of the furnace is provided in the form of a pair of hydraulic cylinders 45 disposed adjacent to the front and at either side of the base frame 12. Each cylinder 45 as herein illustrated, has an upwardly projecting piston rod 46 pivoted at its upper end to a heavy bracket means 47 welded or otherwise suitably secured to the rearwardly facing side of a vertical column 20 by means of a heavy pin 48. The opposite end of each cylinder 45 is pivotally mounted to an upstanding bracket 49 projecting upwardly from Y the associated base plate 11 between the adjacent,

spaced horizontal members 21 by means ofa heavy pin In the retracted position of the cylinders 45 (FIG. 2), the base frame 12 is disposed with the horizontal members 21 flatwise against the base plates 11 and with the column 20 in the vertical position. This positions the induction furnace unit 14 on a vertical axis in which position it tends to stay due to natural pull of gravity. When the cylinders 45 are in the extended position (FIG. 1), the base frame 12 and the furnace 14 are back-tilted whereby the rear slag spout moves upwardly and horizontally rearwardly to a position over the slag box 17. Thus rear slagging can be effected easily above the level of the operating deck D.

Pivoting of the furnace unit 14 for pouring is effected by a pair .of hydraulic cylinders 55 which, in their retracted position are disposed substantially parallel with the axis of the furnace unit 14 substantially midway between the front and rear of said furnace. Each cylinder has an upwardly projecting piston rod 56 journalled at its upper end by a heavy pin 58 to suitable heavy bracket means 57 welded to the bottom surfaces of adjacent pairs of side frame members 27. The lower end of each cylinder 55 is journalled by means of a pin 60 to a bearing member 59 secured to and projecting upwardly from the adjacent pair of horizontal members 21.

When the cylinders 55 are retracted, they position and hold-the furnace unit 14 and the crucible 33 parallel with the upright dimension of the base frame 12 whereby said base frame and furnace unit naturally tend to rest in the vertical position. When the cylinders 55 are in their extended position, as illustrated in FIG. 3, the furnace unit 14 and cradle 13 are pivoted upwardly and forwardly to the curing position. The posi-' tion shown in FIG. 3 is the extreme pouring position for completely emptying the crucible and the furnace may be tilted to any position of lesser tilt desired. From the foregoing it will be readily understood that when the crucible is tilted foreither pouring or slagging, the center of gravity thereof remains rearwardly of the pivot shafts 30 and forwardly of the pivot shafts 43 whereby at all times, the natural tendency of the furnace is to return to the upright vertical position illustrated in broken line in FIG. land in full line in FIG. 2. It is never necessary to secure the furnace against falling into the slagging or pouring position during normal heating operations. Both pouring and slagging in this construction can be carried out above the normal level of the operating deck. Thus, it will be seen that the objects of the invention are fulfilled by the embodiment thereof herein disclosed.

It will be understood that many changes in the details of the invention as herein described and illustrated may be made without, however, departing from the spirit thereof or the scope of the appended claims.

I claim:

1. A back-tilting induction melting furnace assembly having a center of gravity comprising an induction furnace unit normally disposed on a vertical axis for melting, said furnace unit having a forwardly directed pouring spout and a rearwardly directed slag spout; an upright unitary rigid frame having a front portion and a rearwardly extending portion; means pivotally mounting said furnace unit to said frame for pivoting about an axis disposed adjacent to the upper end of and at the front portion of said frame and forwardly of the center of gravity of said furnace unit and frame and adjacent to said pouring spout whereby said furnace unit is pivotable upwardly and forwardly with respect to said frame to pour melt therefrom; and means pivotally mounting the lower end of said frame on a fixed base means rearwardly of the center of gravity of said furnace unit and frame for tilting said frame and said furnace unit rearwardly and upwardly for slagging whereby the center of gravity of said frame and furnace unit is between said two pivotal mounting means.

2. A back-tilting induction melting furnace assembly as set forth in claim 1: said means pivotally mounting said furnace unit comprising a cradle mounted adjacent to the upper end of said furnace unit; said cradle pivoted at its forward end to the upper end of said frame adjacent to the front portion of said frame on an axis transverse to the direction of pouring.

3. Aback-tilting induction melting furnace assembly as set forth in claim 2: power means acting between said frame and said cradle for pivoting said cradle and said furnace unit forwardly for pouring; and power means acting between said frame and said fixed base means for tilting said frame, cradle, and furnace unit rearwardly for slagging.

4. A back-tilting induction melting furnace assembly as set forth in claim 2: said cradle having side members disposed at the sides of said furnace unit adjacent to the upper end thereof; said frame having horizontal members at the bottom side edges thereof; cylinders disposed on eitherside of said furnace unit and connected between said side members and said horizontal members substantially rearwardly of the vertical plane of said transverse axis for pivoting said cradle and furnace unit forwardly for pouring; the rearwardly directed ends of said horizontal members being pivoted on said fixed base means to provide the lower pivot for said frame; and cylinder means connected between the front of said frame and said fixed base means for tilting said frame, cradle, and furnace unit rearwardly for slaggmg.

5. A back-tilting induction melting furnace assembly as set forth in claim 1: power means for pivoting said furnace unit forwardly and upwardly about the axis of said first mentioned pivotal mounting means; and power means for tilting said frame and furnace unit upwardly and rearwardly about the axis ofsaid second mentioned pivotal mounting means.

6. A back-tilting induction melting'furnace assembly having a center of gravity comprising an induction furnace unit normally disposed on a vertical axis for melting, said furnace unit having a forwardly directed pouring spout and an opposite, rearwardly directed slag spout disposed generally at the level of a normal operating deck; an upright unitary rigid frame having a front portion and a rearwardly extending portion; means pivotally mounting said furnace unit to said frame for pivoting about an axis disposed adjacent to the upper end of and at the front portion of said frame forwardly of the center of gravity of said furnace unit and frame and adjacent to said pouring spout whereby said furnace unit is pivotable upwardly and forwardly with respect to said frame to pour melt therefrom above the level of the operating deck; and means pivotally mounting the lower end of said frame on a fixed base means rearwardly of the center of gravity of said furnace unit for tilting said frame and furnace unit rearwardly and upwardly in the opposite direction for slagging above the level of the operating deck, the center of gravity of said furnace being between said two pivotal mounting means whereby said furnace normally tends to return to an upright position. 

1. A back-tilting induction melting furnace assembly having a center of gravity comprising an induction furnace unit normally disposed on a vertical axis for melting, said furnace unit having a forwardly directed pouring spout and a rearwardly directed slag spout; an upright unitary rigid fraMe having a front portion and a rearwardly extending portion; means pivotally mounting said furnace unit to said frame for pivoting about an axis disposed adjacent to the upper end of and at the front portion of said frame and forwardly of the center of gravity of said furnace unit and frame and adjacent to said pouring spout whereby said furnace unit is pivotable upwardly and forwardly with respect to said frame to pour melt therefrom; and means pivotally mounting the lower end of said frame on a fixed base means rearwardly of the center of gravity of said furnace unit and frame for tilting said frame and said furnace unit rearwardly and upwardly for slagging whereby the center of gravity of said frame and furnace unit is between said two pivotal mounting means.
 2. A back-tilting induction melting furnace assembly as set forth in claim 1: said means pivotally mounting said furnace unit comprising a cradle mounted adjacent to the upper end of said furnace unit; said cradle pivoted at its forward end to the upper end of said frame adjacent to the front portion of said frame on an axis transverse to the direction of pouring.
 3. A back-tilting induction melting furnace assembly as set forth in claim 2: power means acting between said frame and said cradle for pivoting said cradle and said furnace unit forwardly for pouring; and power means acting between said frame and said fixed base means for tilting said frame, cradle, and furnace unit rearwardly for slagging.
 4. A back-tilting induction melting furnace assembly as set forth in claim 2: said cradle having side members disposed at the sides of said furnace unit adjacent to the upper end thereof; said frame having horizontal members at the bottom side edges thereof; cylinders disposed on either side of said furnace unit and connected between said side members and said horizontal members substantially rearwardly of the vertical plane of said transverse axis for pivoting said cradle and furnace unit forwardly for pouring; the rearwardly directed ends of said horizontal members being pivoted on said fixed base means to provide the lower pivot for said frame; and cylinder means connected between the front of said frame and said fixed base means for tilting said frame, cradle, and furnace unit rearwardly for slagging.
 5. A back-tilting induction melting furnace assembly as set forth in claim 1: power means for pivoting said furnace unit forwardly and upwardly about the axis of said first mentioned pivotal mounting means; and power means for tilting said frame and furnace unit upwardly and rearwardly about the axis of said second mentioned pivotal mounting means.
 6. A back-tilting induction melting furnace assembly having a center of gravity comprising an induction furnace unit normally disposed on a vertical axis for melting, said furnace unit having a forwardly directed pouring spout and an opposite, rearwardly directed slag spout disposed generally at the level of a normal operating deck; an upright unitary rigid frame having a front portion and a rearwardly extending portion; means pivotally mounting said furnace unit to said frame for pivoting about an axis disposed adjacent to the upper end of and at the front portion of said frame forwardly of the center of gravity of said furnace unit and frame and adjacent to said pouring spout whereby said furnace unit is pivotable upwardly and forwardly with respect to said frame to pour melt therefrom above the level of the operating deck; and means pivotally mounting the lower end of said frame on a fixed base means rearwardly of the center of gravity of said furnace unit for tilting said frame and furnace unit rearwardly and upwardly in the opposite direction for slagging above the level of the operating deck, the center of gravity of said furnace being between said two pivotal mounting means whereby said furnace normally tends to return to an upright position. 